Re: [PATCH v4 06/19] soc: tegra: Add Tegra PMC clock registrations into PMC driver

[Sowjanya Komatineni <skomatineni@nvidia.com>]

On 12/19/19 8:34 PM, Dmitry Osipenko wrote:
> 20.12.2019 07:13, Sowjanya Komatineni пишет:
>> On 12/19/19 5:39 PM, Dmitry Osipenko wrote:
>>> 20.12.2019 04:21, Sowjanya Komatineni пишет:
>>>> On 12/18/19 4:41 PM, Sowjanya Komatineni wrote:
>>>>> On 12/18/19 1:44 PM, Dmitry Osipenko wrote:
>>>>>> 18.12.2019 11:35, Dmitry Osipenko пишет:
>>>>>>> 18.12.2019 11:30, Dmitry Osipenko пишет:
>>>>>>>> 17.12.2019 23:03, Sowjanya Komatineni пишет:
>>>>>>>>> Tegra PMC has clk_out_1, clk_out_2, and clk_out_3 clocks and
>>>>>>>>> currently
>>>>>>>>> these PMC clocks are registered by Tegra clock driver with each
>>>>>>>>> clock as
>>>>>>>>> separate mux and gate clocks using clk_register_mux and
>>>>>>>>> clk_register_gate
>>>>>>>>> by passing PMC base address and register offsets and PMC
>>>>>>>>> programming for
>>>>>>>>> these clocks happens through direct PMC access by the clock driver.
>>>>>>>>>
>>>>>>>>> With this, when PMC is in secure mode any direct PMC access from
>>>>>>>>> the
>>>>>>>>> non-secure world does not go through and these clocks will not be
>>>>>>>>> functional.
>>>>>>>>>
>>>>>>>>> This patch adds these PMC clocks registration to pmc driver with
>>>>>>>>> PMC as
>>>>>>>>> a clock provider and registers each clock as single clock.
>>>>>>>>>
>>>>>>>>> clk_ops callback implementations for these clocks uses
>>>>>>>>> tegra_pmc_readl and
>>>>>>>>> tegra_pmc_writel which supports PMC programming in both secure
>>>>>>>>> mode and
>>>>>>>>> non-secure mode.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>>>>>>>> ---
>>>>>>>>>     drivers/soc/tegra/pmc.c | 248
>>>>>>>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>>>>>>>>     1 file changed, 248 insertions(+)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>>>>>>>>> index ea0e11a09c12..6d65194a6e71 100644
>>>>>>>>> --- a/drivers/soc/tegra/pmc.c
>>>>>>>>> +++ b/drivers/soc/tegra/pmc.c
>>>>>>>>> @@ -13,6 +13,9 @@
>>>>>>>>>       #include <linux/arm-smccc.h>
>>>>>>>>>     #include <linux/clk.h>
>>>>>>>>> +#include <linux/clk-provider.h>
>>>>>>>>> +#include <linux/clkdev.h>
>>>>>>>>> +#include <linux/clk/clk-conf.h>
>>>>>>>>>     #include <linux/clk/tegra.h>
>>>>>>>>>     #include <linux/debugfs.h>
>>>>>>>>>     #include <linux/delay.h>
>>>>>>>>> @@ -48,6 +51,7 @@
>>>>>>>>>     #include <dt-bindings/pinctrl/pinctrl-tegra-io-pad.h>
>>>>>>>>>     #include <dt-bindings/gpio/tegra186-gpio.h>
>>>>>>>>>     #include <dt-bindings/gpio/tegra194-gpio.h>
>>>>>>>>> +#include <dt-bindings/soc/tegra-pmc.h>
>>>>>>>>>       #define PMC_CNTRL            0x0
>>>>>>>>>     #define  PMC_CNTRL_INTR_POLARITY    BIT(17) /* inverts INTR
>>>>>>>>> polarity */
>>>>>>>>> @@ -100,6 +104,7 @@
>>>>>>>>>     #define PMC_WAKE2_STATUS        0x168
>>>>>>>>>     #define PMC_SW_WAKE2_STATUS        0x16c
>>>>>>>>>     +#define PMC_CLK_OUT_CNTRL        0x1a8
>>>>>>>>>     #define PMC_SENSOR_CTRL            0x1b0
>>>>>>>>>     #define  PMC_SENSOR_CTRL_SCRATCH_WRITE    BIT(2)
>>>>>>>>>     #define  PMC_SENSOR_CTRL_ENABLE_RST    BIT(1)
>>>>>>>>> @@ -155,6 +160,64 @@
>>>>>>>>>     #define  TEGRA_SMC_PMC_READ    0xaa
>>>>>>>>>     #define  TEGRA_SMC_PMC_WRITE    0xbb
>>>>>>>>>     +struct pmc_clk {
>>>>>>>>> +    struct clk_hw    hw;
>>>>>>>>> +    unsigned long    offs;
>>>>>>>>> +    u32        mux_mask;
>>>>>>>>> +    u32        mux_shift;
>>>>>>>>> +    u32        gate_shift;
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>> +#define to_pmc_clk(_hw) container_of(_hw, struct pmc_clk, hw)
>>>>>>>>> +
>>>>>>>>> +struct pmc_clk_init_data {
>>>>>>>>> +    char *name;
>>>>>>>>> +    const char *const *parents;
>>>>>>>>> +    int num_parents;
>>>>>>>>> +    int clk_id;
>>>>>>>>> +    u8 mux_shift;
>>>>>>>>> +    u8 gate_shift;
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>> +static const char * const clk_out1_parents[] = { "osc",
>>>>>>>>> "osc_div2",
>>>>>>>>> +    "osc_div4", "extern1",
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>> +static const char * const clk_out2_parents[] = { "osc",
>>>>>>>>> "osc_div2",
>>>>>>>>> +    "osc_div4", "extern2",
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>> +static const char * const clk_out3_parents[] = { "osc",
>>>>>>>>> "osc_div2",
>>>>>>>>> +    "osc_div4", "extern3",
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>> +static const struct pmc_clk_init_data tegra_pmc_clks_data[] = {
>>>>>>>>> +    {
>>>>>>>>> +        .name = "clk_out_1",
>>>>>>>>> +        .parents = clk_out1_parents,
>>>>>>>>> +        .num_parents = ARRAY_SIZE(clk_out1_parents),
>>>>>>>>> +        .clk_id = TEGRA_PMC_CLK_OUT_1,
>>>>>>>>> +        .mux_shift = 6,
>>>>>>>>> +        .gate_shift = 2,
>>>>>>>> I'd replace these with a single .shift, given that mux_shift =
>>>>>>>> gate_shift + 4 for all clocks.
>>>>>>>>
>>>>>>>>> +    },
>>>>>>>>> +    {
>>>>>>>>> +        .name = "clk_out_2",
>>>>>>>>> +        .parents = clk_out2_parents,
>>>>>>>>> +        .num_parents = ARRAY_SIZE(clk_out2_parents),
>>>>>>>>> +        .clk_id = TEGRA_PMC_CLK_OUT_2,
>>>>>>>>> +        .mux_shift = 14,
>>>>>>>>> +        .gate_shift = 10,
>>>>>>>>> +    },
>>>>>>>>> +    {
>>>>>>>>> +        .name = "clk_out_3",
>>>>>>>>> +        .parents = clk_out3_parents,
>>>>>>>>> +        .num_parents = ARRAY_SIZE(clk_out3_parents),
>>>>>>>>> +        .clk_id = TEGRA_PMC_CLK_OUT_3,
>>>>>>>>> +        .mux_shift = 22,
>>>>>>>>> +        .gate_shift = 18,
>>>>>>>>> +    },
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>>     struct tegra_powergate {
>>>>>>>>>         struct generic_pm_domain genpd;
>>>>>>>>>         struct tegra_pmc *pmc;
>>>>>>>>> @@ -254,6 +317,9 @@ struct tegra_pmc_soc {
>>>>>>>>>          */
>>>>>>>>>         const struct tegra_wake_event *wake_events;
>>>>>>>>>         unsigned int num_wake_events;
>>>>>>>>> +
>>>>>>>>> +    const struct pmc_clk_init_data *pmc_clks_data;
>>>>>>>>> +    unsigned int num_pmc_clks;
>>>>>>>>>     };
>>>>>>>>>       static const char * const tegra186_reset_sources[] = {
>>>>>>>>> @@ -2163,6 +2229,173 @@ static int tegra_pmc_clk_notify_cb(struct
>>>>>>>>> notifier_block *nb,
>>>>>>>>>         return NOTIFY_OK;
>>>>>>>>>     }
>>>>>>>>>     +static void pmc_clk_fence_udelay(u32 offset)
>>>>>>>>> +{
>>>>>>>>> +    tegra_pmc_readl(pmc, offset);
>>>>>>>>> +    /* pmc clk propagation delay 2 us */
>>>>>>>>> +    udelay(2);
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static u8 pmc_clk_mux_get_parent(struct clk_hw *hw)
>>>>>>>>> +{
>>>>>>>>> +    struct pmc_clk *clk = to_pmc_clk(hw);
>>>>>>>>> +    u32 val;
>>>>>>>>> +
>>>>>>>>> +    val = tegra_pmc_readl(pmc, clk->offs) >> clk->mux_shift;
>>>>>>>>> +    val &= clk->mux_mask;
>>>>>>>>> +
>>>>>>>>> +    return val;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static int pmc_clk_mux_set_parent(struct clk_hw *hw, u8 index)
>>>>>>>>> +{
>>>>>>>>> +    struct pmc_clk *clk = to_pmc_clk(hw);
>>>>>>>>> +    u32 val;
>>>>>>>>> +
>>>>>>>>> +    val = tegra_pmc_readl(pmc, clk->offs);
>>>>>>>>> +    val &= ~(clk->mux_mask << clk->mux_shift);
>>>>>>>>> +    val |= index << clk->mux_shift;
>>>>>>>>> +    tegra_pmc_writel(pmc, val, clk->offs);
>>>>>>>>> +    pmc_clk_fence_udelay(clk->offs);
>>> Is this fencing applies only to clock changes or maybe it won't hurt to
>>> move it into tegra_pmc_writel()?
Only for clock changes
>>>
>>>>>>>>> +    return 0;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static int pmc_clk_is_enabled(struct clk_hw *hw)
>>>>>>>>> +{
>>>>>>>>> +    struct pmc_clk *clk = to_pmc_clk(hw);
>>>>>>>>> +
>>>>>>>>> +    return tegra_pmc_readl(pmc, clk->offs) & BIT(clk->gate_shift)
>>>>>>>>> ? 1 : 0;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static void pmc_clk_set_state(unsigned long offs, u32 shift, int
>>>>>>>>> state)
>>>>>>>>> +{
>>>>>>>>> +    u32 val;
>>>>>>>>> +
>>>>>>>>> +    val = tegra_pmc_readl(pmc, offs);
>>>>>>>>> +    val = state ? (val | BIT(shift)) : (val & ~BIT(shift));
>>>>>>>>> +    tegra_pmc_writel(pmc, val, offs);
>>>>>>>>> +    pmc_clk_fence_udelay(offs);
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static int pmc_clk_enable(struct clk_hw *hw)
>>>>>>>>> +{
>>>>>>>>> +    struct pmc_clk *clk = to_pmc_clk(hw);
>>>>>>>>> +
>>>>>>>>> +    pmc_clk_set_state(clk->offs, clk->gate_shift, 1);
>>>>>>>>> +
>>>>>>>>> +    return 0;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static void pmc_clk_disable(struct clk_hw *hw)
>>>>>>>>> +{
>>>>>>>>> +    struct pmc_clk *clk = to_pmc_clk(hw);
>>>>>>>>> +
>>>>>>>>> +    pmc_clk_set_state(clk->offs, clk->gate_shift, 0);
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static const struct clk_ops pmc_clk_ops = {
>>>>>>>>> +    .get_parent = pmc_clk_mux_get_parent,
>>>>>>>>> +    .set_parent = pmc_clk_mux_set_parent,
>>>>>>>>> +    .determine_rate = __clk_mux_determine_rate,
>>>>>>>>> +    .is_enabled = pmc_clk_is_enabled,
>>>>>>>>> +    .enable = pmc_clk_enable,
>>>>>>>>> +    .disable = pmc_clk_disable,
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>> +static struct clk *
>>>>>>>>> +tegra_pmc_clk_out_register(const struct pmc_clk_init_data *data,
>>>>>>>>> +               unsigned long offset)
>>>>>>>>> +{
>>>>>>>>> +    struct clk_init_data init;
>>>>>>>>> +    struct pmc_clk *pmc_clk;
>>>>>>>>> +
>>>>>>>>> +    pmc_clk = kzalloc(sizeof(*pmc_clk), GFP_KERNEL);
>>>>>>>>> +    if (!pmc_clk)
>>>>>>>>> +        return ERR_PTR(-ENOMEM);
>>>>>>>>> +
>>>>>>>>> +    init.name = data->name;
>>>>>>>>> +    init.ops = &pmc_clk_ops;
>>>>>>>>> +    init.parent_names = data->parents;
>>>>>>>>> +    init.num_parents = data->num_parents;
>>>>>>>>> +    init.flags = CLK_SET_RATE_NO_REPARENT | CLK_SET_RATE_PARENT |
>>>>>>>>> +             CLK_SET_PARENT_GATE;
>>>>>>>>> +
>>>>>>>>> +    pmc_clk->hw.init = &init;
>>>>>>>>> +    pmc_clk->offs = offset;
>>>>>>>>> +    pmc_clk->mux_mask = 3;
>>>>>>>> If mux_mask is a constant value, perhaps will be better to
>>>>>>>> replace the
>>>>>>>> variable with a literal?
>>>>>>>>
>>>>>>>> #define PMC_CLK_OUT_MUX_MASK    GENMASK(1, 0)
>>>>>>> Maybe even:
>>>>>>>
>>>>>>> #define PMC_CLK_OUT_MUX_MASK(c)    GENMASK(c->shift + 1, c->shift)
>>>>> MUX Mask is used only here for PMC clock out and is same for all
>>>>> clk_out mux so will use
>>>>>
>>>>> #define PMC_CLK_OUT_MUX_MASK    GENMASK(1, 0)
>>>>>
>>>>>> I want to point out that may be a separated gate/mux shifts is a fine
>>>>>> variant, you should try and see whether another variants produce more
>>>>>> concise result.
>>>>>>
>>>>>> [snip]
>>>> We can do mux_shift as gate_shift + 4 and that restricts this clk
>>>> register only for clk1/2/3 as well and there are no other clocks in pmc
>>>> anyway.
>>>>
>>>> How about using bit shift define for CLK1, CLK2, and CLK3?
>>>>
>>>> .mux_shift = PMC_CLK1_SRC_SEL_SHIFT,
>>>>
>>>> .gate_shift = PMC_CLK1_FORCE_EN_SHIFT,
>>>>
>>>>
>>> I think that just renaming ".gate_shift" -> ".force_en_shift" should be
>>> good enough.
>> You meant to assign bit position directly instead of defines like what I
>> have now in v4 and use force_en_shift instead of gate_shift?
> Yes